Secondary-injection thrust vector control valve



Feb. 7, 1957 A. B. HOLMES ETAL 3,302,888

SECONDARY-INJECTION THRUST VECTOR CONTROL VALVE Filed May 25, 1965INVENTOES,

7 ALLEN 5. HOLMES Jam/5. fioxwsu.

A 1 TOIYNE 7s United States Patent O Filed May 25, 1965, Ser. No.459,981 2 Claims. (Cl. 239-26513) The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment to us of anyroyalty thereon.

This invention relates generally to supersonic, threedimensional fluidamplifiers, and more particularly to a fluid amplifier thrust vectorcontrol system for reaction jet engines.

One way to steer or control jet-propelled vehicles is thrust vectorcontrol. Basically, thrust vector control means control by deflection ofthe main propulsion jet. One way to do this is by secondary fluidinjection; that is, an auxiliary fluid is injected into the mainreaction jet nozzle, causing the main propulsion jet to deflect. A fewexamples of systems of this type may be found in the patents toWetherbee, Patent No. 2,943,821; Walker, Patent No. 2,916,873; andKadosch et al., Patent No. 2,812,636.

To get good control of reaction jet engines by means of secondaryinjection thrust vectoring, it is necessary to have available at eachsecondary injection nozzle about six percent of the main reaction trustjet. This amount of fluid is necessary to give quick response under fullcontrol conditions. Very often, in prior systems, the secondaryinjection fluid is an auxiliary fluid, carried separately, specially forcontrol purposes. While in many applications this system issatisfactory, there is a sacrifice in overall efliciency because of theincreased nonthrust-producing weight. An inherently more attractivesystem is to bleed the reaction products from the combustion chamber ofthe engine for use as secondary injection fluid. With this system, noauxiliary control fluid is needed, and overall efliciency andperformance are enhanced. Bleed system proposals, however, have beenaround for a number of years, and yet, as far as the applicants areaware, no really satisfactory system is available. The problem lies incontrolling the hot-gas, high-velocity, reaction prod ucts from thecombustion chamber with the precision required for the thrust vectorcontrol.

In another co-pending application Serial No. 352,695, filed March 17,1964, in which the applicants of the present invention are co-inventorswith another and which is assigned to the assignee of the presentapplication, there is disclosed a novel one-leg fluid amplifier controlsystem. This system includes a supersonic jet-forming nozzle with itsflow axis unobstructed so that the full reaction thrust of the nodzlemay be developed. Displaced from one side of the main jet flow axis is asplitter and fiuid catcher channel. On the same side of jet axis ismeans to proportionately control the amount of entrainment of the jetformed by the supersonic nozzle. The proportionate control means has nomoving parts in the hot-gas stream, but,- by controlling the amount ofentrainment, it is effective to control the amount of fluid whichimpinges on the splitter and is directed into the catcher channel.

3,3i2,888 Patented Feb. 7, 1967 The particular proportionate controlmeans is an atmospheric bleed valve. While this sytsem has functionedWell it has become evident that the usefulness of the sys tem falls oifwith increasing altitude because of the lack of atmospheric air toprovide a pressure gradient for switching.

It is therefore an object of this invention to provide athree-dimensional, supersonic proportional control fluid amplifiercapable of controlling react-ion jet engines at high altitudes.

It is another object of the instant invention to provide a combustionchamber bleed, secondary injection, thrust vector control system forreaction jet engines which has no moving parts in the hot-gas stream andwhich is capable of operation both within and without the earthsatmosphere. 7

It is a further object of this invention to provide a reaction chamberbleed, t-hrust vector control system which provides continuousproportionate control of the injection gas from full-on t'o full-offindependent of altitude.

According to the present invention, these and other objects areaccomplished by providing within the control system disclosed in theaforementioned application Serial No. 352,695 a pressure suppliedcont-r01 nozzle placed so as to be diametrically opposed to theatmospheric bleed control port.

The specific nature of the invention, as well as other objects, aspects,uses and advantages thereof, will clearly appear from the followingdescription and from the accompanying drawing, in which:

FIG. 1 is a perspective view of a one-leg, three-dimensional, supersonicfluid amplifier according to this invention;

FIG. 2 is a sectional schematic view of a one-leg, fluid amplifieraccording to this invention; and

FIG. 3 is a sectional schematic view of a thrust vector control systemaccording to this. invention.

Referring now to the drawing in which like reference numerals designatesimilar or identical parts throughout, and more particularly to FIGS. 1and 2, which show a one-leg, fluid amplifier which includes aconvergingdiverging nozzle 12 and having a mounting flange 13 forattachment to a reaction chamber bleed port. The nozzle 12 has anorifice 15 with a principal jet thrust axis along the line 14. Locateddownstream from the nozzle orifice 15 is a splitter 18. The splitter 18is located far enough to one side of the principal thrust axis 14 thatvirtually none of the jet stream issuing from nozzle 12 impinges uponthe splitter in the absence of a control signal. On the same side of theprincipal thrust axis 14 as the splitter 18 is a fixed system 19 forproportionately controlling the amount of fluid jet stream directed intoa conduit or channel 17. The fixed system 19 includes a channel 21extending out from the diverging portion of the nozzle 12. As is shown,there is a control port 24 in the channel 21 closely adjacent the nozzle12. Separated from the port 24 by a channel 25 is an entrainment controlvalve 23 which is in communication with atmosphere via the chambersurrounding it (as seen in FIG. 3). By limiting the amount of air flowthrough the valve 23, the jet stream will be deflected from the axis 14toward the splitter 18; that is, as the valve 23 is gradually closed,limiting the amount of air supplied to port 24, the jet stream issuingfrom nozzle 12 is proportionately directed toward the "3 J splitter 18.With the valve 23 closed, substantially the entirejet stream is directedinto channel 17.

The mechanism of operation of the fluid amplifier shown in FIGS. 1 and 2is due to the Coanda eflect. In his Patent No. 2,052,869, Henri Coandapoints out that when a fluid jet issues through a suitable nozzle intoanother fluid, such as air, it will carry along with it a portion of thesurrounding fluid if its velocity is sufficient. In other words, the jetwill create a suction effect on the surrounding fluid at the point ofdischarge from the nozzle. It, at the outlet of the nozzle, there is setup an unbalancing effect on the flow of surrounding air induced by thejet, the jet will move towards the side on which the flow of thesurrounding fluid has been made more difficult.

The fluid amplifier described in FIGS. 1 and 2 applies the principles ofthe Coanda effect in three dimensions. Channel 21 is rigidly attached tonozzle 12, and the side walls of channel 21 are of suflicient height toprevent entrainment in the lateral direction. With the valve 23 closed,or partially closed, there will be a greater pressure on the jet issuingfrom the nozzle 12 on the side away from splitter 18 due to the lowerpressure at port 24 caused by the restricted entrainment. This unbalancein pressure deflects the jet forward splitter 18. The jet issuing fromnozzle 12 will have a supersonic velocity when the pressure ratio acrossnozzle 12 is greater than 2. This pressure ratio will, of course, bepresent when the fluid is supplied from the combustion chamber of areaction jet engine. A supersonic jet will induce a large amount ofentrainment of the surrounding air, and this high entrainmentcharacteristic gives a high degree of control to valve 23.

The fluid amplifier thus far disclosed is that disclosed in theaforementioned application Serial No. 352,695. This invention providesan additional fluid control nozzle 27 located diametrically oppositeport 24. The nozzle 27 is supplied with a fluid under pressure from anauxiliary fluid source (not shown) by way of a conduit or channel 28.Fluid issuing from nozzle 27 interacts with the jet issuing from nozzle12 causing the jet to deflect toward channel 21. Assuming the fluidissuing from nozzle 27 is under a constant pressure, the angle ofdeflection of the jet is dependent on the quantity or mass of the fluidissuing from nozzle 27. The quantity of fluid supplied to nozzle 27 byway of channel 28 may be controlled by any well known valving mechanism.

The addition of nozzle 27 eliminates the inherent altitude limitationsof the control system disclosed in application Serial No. 352,695 andallows the system to function etficiently at very high altitudes. Thus,as the effectiveness of the valve 23 decreases with increasing altitude,deflection of the jet issuing from nozzle 12 may be gradually andincreasingly produced by fluid caused to issue from control nozzle 27.Since only a small amount of fluid issuing from control nozzle 27 isrequired to deflect the jet issuing from nozzle 12, and since control ofthe jet issuing from nozzle 12 by means of fluid issuing from nozzle 27is required only in high altitude operation, the source of auxiliaryfluid under pressure is minimal.

The offset of the splitter 18 from the thrust axis 14 and its distancefrom the nozzle 12 are primarily determined by the characteristics ofthe jet issuing from nozzle 12, which in turn is determined by thenozzle design and the supply fluid characteristics. That is, the oflsetshould be suflicient that no fluid impinges on the splitter 18 whenvalve 23 is opened, yet the splitter 18 should be close enough to nozzle12 that the jet stream is still moving at supersonic volocity when itenters the channel 17.

FIGURE 3 shows the control system of this invention to control areaction jet engine. The reaction jet engine has a combustion chamber31, with a converging-diverging power nozzle 32. The principal thrustaxis of the engine is along the axis 33. To control the jet engine andthe vehicle which it powers there are thrust vector control systems 35and 36. While only two systems are shown, it will be obvious to thoseskilled in the art that an actual system would ordinarily employ fourunits-one unit for each directionin order to achieve three-dimensionalcontrol. The broad function of the control systems 35 and 36, which areidentical, is to bleed a proportion of the reaction products from thecombustion chamber 31 through ports 37 and inject a controlled amount ondemand into main reaction nozzle 32 through thrust vectoring nozzles 38.In order to achieve good control it is usually necessary that about sixpercent of the main rocket thrust in pounds be available at each controlnozzle. This requires that each control system such as 35 or 36 becapable of channeling a significant amount of fluid to the secondarycontrol nozzles under full control conditions.

In order that the thrust vector control system 35 and 36 be efficient,the auxiliary control nozzles 12 have their principal thrust axissubstantially parallel to the main rocket thrust axis 33. In FIGURE 3,the axes 14 are actually inclined slightly with respect to the axis 33in order that the control system thrust axis 14 pass through the centerof gravity of the engine so that the control system does not create aturning moment on the engine. This is not absolutely necessary, since asis apparent, if the units 35 and 36 are balanced even though the thrustaxis 14 is parallel to axis 33, the turning moments will cancel.

With no control, substantially the full forward thrust of the engine isdeveloped in the main jet nozzle 32 and the auxiliary control nozzles12. When it is desired to deflect the principal thrust jet issuing fromnozzle 32, one of the valves 23, for example of system 36, is closed anamount proportional to the distance the main jet is to be directed awayfrom its axis 33. With the valve 23 partially closed, part of the jetstream from nozzle 12 is directed to the channel 17 and issues fromthrust control nozzle 38, while the remainder of the jet stream isdirected substantially along the main axis 33 providing propulsionpower. At higher altitudes, fluid from the control nozzle 27 is causedto issue against the jet issuing from nozzle 12. The amount of the fluidissuing from control nozzle 27 is made to be proportional to thedistance the main jet is to be deflected away from its axis 33, asbefore.

As will be apparent to those skilled in the art, the applicants haveprovided an efficient thrust vector control system which can providecontinuous proportionate control of. the main thrust jet either withinor without the earths atmosphere. This control system does not requiremoving parts in any hot-gas path. In terms of the present state of theart, this in combination with the high thrust recovery of the system inthe absence of a control signal makes this system a very practical andoperative one. The gain of the applicants fluid amplifier system canmost significantly be measured in terms of flow; that is, the ratio ofcontrol flow and change in pressure through valve 23, or fluid flowthrough control port 27, to the change of fluid jet flow in pressurethrough conduit 17. Gains on the order of 10,000 have been realized withsystems of the type described.

It will be apparent that the embodiment shown is only exemplary and thatvarious modifications can be made in construction and arrangement withinthe scope of the invention as defined in the appended claims.

We claim as our invention:

1. A secondary injection, thrust vector system for use with a reactionjet engine which has a combustion chamber and a main reaction jet nozzlewith a thrust axis, comprising:

(a) a bleed connected to said combustion chamber,

(b) an auxiliary control nozzle connected to said bleed and having anunobstructed principal thrust axis along which an auxiliary control jetissues,

(c) a semi-cylindrical section connected to said control nozzle andextending therefrom to form an open channel and being located on oneside of said principal thrust axis,

(d) a splitter located Wholly on the same side of said principal thrustaxis as said open channel,

(e) first control means for controlling the direction of said auxiliarycontrol jet including a passage connected to atmosphere and having aport leading into said open channel,

(f) a fluid conduit connected to said main reaction jet nozzle, saidsplitter adapted to direct a portion of said auxiliary jet impingingthereon to said conduit, and

(g) auxiliary control means for controlling the direction of saidauxiliary jet including a pressure fluid supplied nozzle opposite theprincipal axis of said auxiliary nozzle from said first control meansand effective to progressively control said auxiliary jet when saidfirst control means is ineffective because of high altitudes.

2. A device according to claim 1 wherein valve means are located in saidfirst control means passage to progressively control the movement ofsaid auxiliary jet.

References Cited by the Examiner OTHER REFERENCES Fluid Oscillator, byA. E. Mitchell, I.B.M. Technical Disclosure Bulletin, vol. 5, No. 6,November 1962, page 25.

Fluid Control Device by Stanley W. Angrist, Scientific American,December 1964, pages 82, 83 and 86.

CARLTON R. CROYLE, Primary Examiner.

SAMUEL FEINBERG, Examiner.

1. A SECONDARY INJECTION, THRUST VECTOR SYSTEM FOR USE WITH A REACTIONJET ENGINE WHICH HAS A COMBUSTION CHAMBER AND A MAIN REACTION JET NOZZLEWITH A THRUST AXIS, COMPRISING: (A) A BLEED CONNECTED TO SAID COMBUSTIONCHAMBER, (B) AN AUXILIARY CONTROL NOZZLE CONNECTED TO SAID BLEED ANDHAVING AN UNOBSTRUCTED PRINCIPAL THRUST AXIS ALONG WHICH AN AUXILIARYCONTROL JET ISSUES, (C) A SEMI-CYLINDRICAL SECTION CONNECTED TO SAIDCONTROL NOZZLE AND EXTENDING THEREFROM TO FORM AN OPEN CHANNEL AND BEINGLOCATED ON ONE SIDE OF SAID PRINCIPAL THRUST AXIS, (D) A SPLITTERLOCATED WHOLLY ON THE SAME SIDE OF SAID PRINCIPAL THRUST AXIS AS SAIDOPEN CHANNEL, (E) FIRST CONTROL MEANS FOR CONTROLLING THE DIRECTION OFSAID AUXILIARY CONTROL JET INCLUDING A PASSAGE CON-